Magnetic head support gimbal having arcuate side rails

ABSTRACT

The invention is aimed at miniaturization and thinning of a magnetic head support device of a floating type. The magnetic head support device includes a load beam 3 having upstanding side rails 22 extending along the longitudinal side edges of the load beam. The magnetic support device also includes a gimbal 2 having upstanding side rails 21 extending along the longitudinal edges of the gimbal for a predetermined distance. The gimbal 2 is disposed below the load beam 3. The upper edges of the side rails 21 of the gimbal are engaged with the lower surface of the load beam 3, so that a predetermined spacing is maintained as between the lower surface of the load beam and the upper surface of the gimbal 2.

FIELD OF THE INVENTION

This invention relates to a magnetic head support device of a floatingtype. More particularly, the invention relates to a provision of meansfor miniaturizing and thinning a gimbal to be used in a magnetic headsupport device of a floating type as an attachment member for a slider.

BACKGROUND OF THE INVENTION

A magnetic head support device of an information processing unit forsupporting a magnetic head over a magnetic disk so as to performrecording and reproducing of information comprises, as shown in FIG. 3,a slider 1 having a magnetic head thereon, a gimbal 2 for supporting theslider 1 for rolling motion, and a load beam 3 supporting the gimbal 2.More particularly, the gimbal 2 is attached to the forward end of theload beam 3 for rolling motion by means of fastening means such as welds5. The gimbal 2 is formed from a thin, electrically conductive plate,such as a thin plate of phosphor bronze. A semi-spherical protrusion 4is formed on the upper surface of the gimbal 2. The protrusion 4 is aconstructional member of the magnetic head for permitting the slider 1having the magnetic head thereon to be rolled in accordance with theirregularities on the surface of the magnetic disk so as to performrecording and reproducing magnetic information.

With the conventional magnetic head support device of a floating type 10as shown in FIGS. 3A and 3B, a semi-spherical protrusion 4 is welded tothe upper surface of a tongue portion 2A for attachment of the sliderthereon. The tongue portion 2A extends from the distal end toward theproximal end of the gimbal 2 in a cantilever fashion. Thus, when themain body of the gimbal 2 has a thickness of 30 micrometers and theprotrusion 4 has a height of 140 micrometers, the total thickness of thegimbal 2 and the protrusion 4 at the tongue portion 2A will be 170micrometers. Generally, the gimbal 2 is set at a thickness of 25 to 50micrometers. Thus, when the thickness of the gimbal 2 is selected to be50 micrometers, the total thickness of the gimbal 2 and the protrusion 4at the tongue portion 2A will reach up to 190 micrometers. Thus, inconventional technique, the magnetic head support device 10 as asuspension unit will have a increased thickness corresponding to theheight of the protrusion 4 even when the thickness of the gimbal 2 isreduced. This impairs miniaturizing and thinning of the magnetic headsupport device.

SUMMARY OF THE INVENTION

This invention is aimed at reduction of the thickness of the suspensionunit by obviating the protrusion 4 which has been consideredindispensable to the conventional magnetic head support device 10 of afloating type, so as to obtain an improved magnetic head support deviceof a floating type in terms of miniaturization and thinning effects.

In order to achieve the above object, the invention provides a magnetichead support device comprising a gimbal connected to the distal end of aload beam. The gimbal is formed from a thin metal plate. The gimbalincludes a distal end portion formed in an attachment portion for aslider having a magnetic head thereon. The gimbal is disposed below theload beam. The load beam includes upstanding side rails extending alongthe longitudinal side edges of the load beam. The gimbal includesupstanding side rails extending along the longitudinal side edges of thegimbal for a predetermined distance. The upper edges of the side railsof the gimbal are engaged with the lower surface of the load beam, sothat a predetermined spacing is maintained between the lower surface ofthe load beam and the upper surface of the gimbal.

The upper edges of the side rails extending along the longitudinal sideedges of the gimbal may be formed into an arcuate configuration. Thearcuate upper edges serve as means for increasing rolling ability of theslider.

Stepped portions may be formed in the gimbal body at positions proximalof the side rails of the gimbal. The stepped portions extend across thegimbal body. The stepped portions serve as gap prevention means forpreventing the distal end portion of the gimbal from being spaced apartfrom the lower surface of the load beam.

The load beam includes upstanding side rails extending along thelongitudinal side edges of the load beam. The gimbal also includesupstanding side rails extending the longitudinal side edges of thegimbal for a predetermined distance. The gimbal is disposed below theload beam. The upper edges of the side rails of the gimbal are engagedwith the lower surface of the load beam. By this, a predeterminedspacing is maintained between the lower surface of the load beam and theupper surface of the gimbal. The spacing permits the slider to besupported for rolling motion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a gimbal body according to theinvention;

FIG. 1A' is a perspective view of a gimbal body according to a secondembodiment of the invention;

FIG. 1 (B) is a perspective view of a load beam;

FIG. 2A is a perspective view illustrating weld construction of amagnetic head support device of a floating type;

FIG. 2B is a cross-sectional view showing the gimbal body and the loadbeam;

FIG. 2C is a front view illustrating the gimbal body spaced from theload beam;

FIG. 2D is a front view illustrating the gimbal body having steppedportion and load beam;

FIG. 3A is a front view showing conventional magnetic head supportdevice; and

FIG. 3B is a plan view showing the conventional magnetic head supportdevice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

One embodiment of the invention will be explained in detail below withreference to FIGS. 1A, 1A', 1B and 2A-2D. It is noted that thecomponents in these figures that are conventional are basicallydesignated by the same reference numerals as in FIGS. 3A, 3B in order toeliminate repetitive explanation.

A magnetic head support device 20 of a floating type according to theinvention includes a load beam 3 having a pair of upstanding side rails22 extending along the opposite left-hand and right-hand longitudinalside edges of the load beam 3, as shown in FIG. 1B. FIGS. 2B-2D show agimbal body 2 is disposed below the load beam 3. The gimbal body 2includes a pair of upstanding side rails 21 extending along the oppositeleft-hand and right-hand longitudinal side edges of the gimbal body 2for a predetermined distance L0 or L'0 as shown in FIGS. 1A and 1A'. Asshown in FIGS. 2A and 2B, the side rails 21 of the gimbal body 2 areengaged at their upper edges with the lower surface of the load beam 3,so that a predetermined spacing L is maintained as between the lowersurface of the load beam 3 and the upper surface of the gimbal body 2.The spacing L permits rolling motion of the slider 1 attached to thelower surface of the distal end portion of the gimbal body 2. Thus,tracking ability or following ability of a magnetic head relative to theirregularities on a surface of a magnetic disk (not shown) may bemaintained at a high level, notwithstanding the fact that a protrusion 4employed in prior art device is not formed in the upper surface of atongue portion 2A to which the slider is mounted.

The upper edges of the side rails 21 having the distance L0 or L'0 alongthe longitudinal side edges of the gimbal body 2 is in general formedinto a linear configuration. It is noted, however, that the upper end ofthe side rail 21A may be formed into an arcuate configuration as shownin FIG. 1A' in order to facilitate rolling motion of the slider 1. Bythis, contact area between the lower surface of the load beam 3 and theupper surface of the gimbal body 2 is increased so that rolling abilityof the magnetic head is increased.

When the gimbal body 2 is formed into a linear configuration as viewedalong the longitudinal cross-section, as shown in FIG. 2C, and when theproximal end portion of the gimbal body 2 is welded to the proximal endportion of the load beam 3, it is possible for the distal end portion ofthe side rail 21 or 21A of the gimbal being spaced from the lowersurface of the load beam, so that a gap G is formed therebetween (FIG.2C). Such a gap may give adverse effect to rolling ability of themagnetic head. Thus, it is desirable to employ means for preventingoccurance of such a gap. FIG. 2D illustrates one example of such gapprevention means. The gap prevention means includes stepped portions 24formed in the gimbal body 2 at a respective position proximal of theside rail 21 or 21A of the gimbal body. The stepped portions extend inthe direction of width of the gimbal body 2. The stepped portions have aheight less than the thickness of the gimbal body 2 plus the height ofthe side rail 21 or 21A. The stepped portions 24 may serve as gapprevention means to prevent the distal end portion of the gimbal body 2from being spaced from the lower surface of the load beam 3.

According to the invention, and since it is unnecessary for theprotrusion of a semi-spherical configuration to be formed in the uppersurface of the gimbal, the total thickness of the suspension unit may bereduced by the height of the protrusion less the above gap L, when agimbal having a thickness the same as that in the conventional techniqueas shown in FIGS. 3A, 3B is employed. When the gap L is set to be 50micrometers, the thickness of the slider attachment portion of a singlesuspension unit is reduced by the amount of 140 micrometers minus 50micrometers, i.e., 90 micrometers by reason of absence of the protrusionhaving a height of 140 micrometers. It is common for a magnetic headsupport device of a floating type to employ a plurality of suspensionunits in a stacked manner in order to obtain an increased recording andreproducing capacity. Thus, in a magnetic head support device of afloating type employing eight-stage suspension units, its height may bereduced by the amount of 720 micrometers compares with the conventionaltechnique, so that miniaturization and thinning of the device areachieved, without affecting rolling capability and support rigidity ofthe slider.

Thus, the invention contributes to thinning of a suspension unit for usein a magnetic head support device of a floating type applicable to highdensity magnetic disks having a diameter of 2.5 inches or less, so as topermit miniaturization and thinning of a hard disk device.

I claim:
 1. A magnetic head support device comprising:a load beam havinga central planar portion defined by first and second surfaces; a gimbalhaving a central planar portion positioned in underlying, alignedrelation with the load beam, the gimbal being cantilever mounted to theload beam at corresponding first ends; a pair of upstandingforeshortened parallel side rails integrally extending from lateral edgeportions of the gimbal; each of the side rails having a C-shapedtransverse cross section and an arcuate outer edge generallylongitudinal with the length of the gimbal; the arcuate edge of thegimbal normally contacting the first surface of the load beam tofacilitate rolling of the gimbal over the arcuate edge, in response toflexure of the gimbal, thereby enhancing the flexibility of the gimbal;the first surface of the load beam normally resting at a spaced distancewith respect to a confronting first surface of the gimbal; and thesecond surface of the load beam mounting a slider bearing a magnetichead thereon.
 2. A magnetic head support device as set forth in claim 1wherein the gimbal has a stepped offset formed along an intermediatetransverse line therealong to maintain aligned second ends of the gimbaland the load beam in contact with each other.